Mealworm Mass death

[benga]

It all began when I went cross country for vacation. I left my gecko and my mealworm colony in my brother's hands. Chances of something happening to the colony were slim, I mean just change out the foods in the bin every week and that's it.

So I come back from vacation and my brother did just that. But when I looked into the bin i saw a bunch of black lines. Those black lines were dead mealworms. I'd say about 70% of them were dead in all of my bins. I couldn't figure out what happened.

I'm here to ask you what would do this? Ever since then my colony is barely thriving. The colony was strong for about half a year till this all happened. It's like the black plague hit my worms.

 

[acpart]

The only things I can think of are:
--poor reaction to food (if he fed them anything different). I once lost multiple batches of mealworms after feeding them home-made gutload (from the health food store, no less). I think I overdid it on oily/fatty seeds and grains and they smothered
--mold or fungus getting into the gutload.
--some contaminant getting into the gutload

Aliza

 

[specialtyreptile]

too hot/cold temps... lack of or too much moisture... overcrowding ???